1. Field of the Invention
This invention relates to a single-sided abrasion apparatus which abrades, by means of a platen, one side of a work piece having a substantially flat face, such as electronic parts like semiconductor wafers, glass wafers, magnetic disc bases, and others or mechine parts, and more particularly to a single-side abrasion apparatus that has the dresser to correct the working face of a platen.
2. Discussion of the Background
A single-side abrasion apparatus having a platen that is driven and freely rotated by a motor, an application block to which a work piece to be abraded is applied, and a plurality of pressing plates which press the work on the platen with the application block in between at the required processing pressure, has been widely known.
If such a single-side abrasion apparatus is used, the working face of the platen must be corrected regularly because abrasion precision is lowered by the worsening conditions of the working face: the evenness of the platen diminishes as the work piece is abraded, or if a pad is used, the pad is clogged or abraded nonuniformly, and the like.
In order to correct the working face of the platen, conventionally an exclusive dresser was separately provided and fitted in the pressing plates, then pressed on the platen.
However, if the exclusive dresser is mounted on or removed from the pressing plates as described above, mounting and removing the dresser is extremely troublesome and workability is poor; especially when an oversized single-side abrasion apparatus is used, the dresser is necessarily large and heavy, and as a dresser too large to be moved by one person is often used, thus making mounting and removing of the dresser more troublesome and dangerous.
Moreover, when the dresser is not used, it must be stored near the abrasion apparatus, which means that it is necessary to maintain space to store the dresser, and to transport the dresser.